Vat dyestttff and process of making same



Reissuecl Nov. 1, 1932 UNITED STATES 'WILHELM ECKERT AND HEINRICH GRETTTNE, OF FRANKFORT-ON-THE-MAIN-HOCHST,

GERMANY, ASSIGNOR T GENERAL ANILINE DELAWARE WORKS, INC., A CORPORATION OF VAT DYES'I'UFF AND PROCESS OF MAKING SAME No Drawing. Original No, 1,588,451, dated June 15, 1926, Serial No. 44,369, filed July 17, 1925, and in Germany July 21, 1924. Application for reissue filed April 8, 1930. Serial No. 442,678.

We have found that new valuable mixtures of vat dyestuffs are obtainable by condensing the dianhydride of 1.4.5.8-naphthalenetetra-carboxylic acid, or this acid itself or its substitution products, with an ortho-d1- amine or a salt of it. The new dyestufi' mixtures are distinguished by the beautiful shades they give, and their excellent properties as to fastness.

It could not be expected that mixtures of vat-dyestuffs are obtainable by means of naphthalenetetra-carboxylic acid, because 1.4.5.8-napthalenetetra-carboxylic acid used as parent product is a perfectly White body to which, even if it is transformed into the di-imide, cannot be imparted the characteristic properties of a dyestuif.

The following example illustrates our invention, the parts being by weight:

10 parts of the dianhydride of 1.4.5.8-

naphthalenetetra-carboxylic acid are heated in parts of nitrobenezene with 20 parts of ortho-phenylenediamine until the product resulting from the reaction is entirely sepa- 25 rated. This product is filtered off by suction and washed with alcohol until the excess of ortho-phenylenediamine is entirely eliminated. The new product forms, when dry, a bright red powder which dissolves in concentrated sulfuric acid to a yellowishbrown solution. It gives a green vat which dyes cotton the same color which, when the material is exposed to the air, changes to a brilliant red tint with a yellow hue.

If for the ortho-phenylenediamine is substituted 4-chloro-1.Q-diaminobenzene and the further operations are carried out as above indicated, a product is obtainable which dyes cotton from a green vat a green tint which, when the material is exposed to the air,

changes to a bright reddish brown shade of excellent fastness.

From 4-nitro-1.Q-diaminobenzene and 1.4.- 5.8.-naphthalenetetra-carboxylic acid or its anhydride a product is obtainable as a. brown powder, which dissolves in concentrated sulfuric acid to a yellow solution with an intense green fluorescence. The vat prepared therefrom is of a green'color and dyes cotton the same color which, when the material is exposed to the air, changes to a grey to black tint.

In the same manner there may be condensed instead of the bases themselves their salts, particularly the hydrochlorides, with naphthalene-1.4.5.8-tetra-carboxylic acid or its anhydride.

Instead of condensing a naphthalene- 1.t.5.8-tetra-carboxylic acid halogenated or not, with a halogenated ortho-phenylenediamine substituted or not, the finally formed condensation products partially containing or not containing halogen, may afterwards be halogenated. The halogenation may be effected by suspending the condensation prodnot in a diluent, such as nitrobenzene, and introducing for instance a gentle current of chlorine into the mass while heating to about l-180 0. Finally the mass is isolated in the usual manner.

The chlorinated product thus obtained dissolves in concentrated sulfuric acid with a red color and dyes cotton from a green vat a reddish-brown tint.

As 1.4.5.8-naphthalenetetra-carboxylic acid reacts in essentially the same manner as the anhydride, we understand by the term 1.4.5.8 naphthalenetetra carboxylic' acid, used in the following claims, not only this acid itself but also its anhydride, and by an grtho-diamine we understand also the salts o it.

The condensation may also be efi'ected in absence of a solvent or diluent with the same result by melting together for a short time both components.

Our experiments have shown that the products obtainable by the above described process are not products of uniform chemical composition but represent in many cases mix- :ence of the substituent. p

tures of isomeric compounds formed by the reaction. When condensing for instance the dianhydride LL58 naphthalenetetra-carboxylic acid with ortho-phenylenediamine a product is obtained which represents a mixture of the two isomeric dyestuffs of the following formulae:

\Vhen using instead of ortho-phenylenediamine a substitution product thereof in most cases likewise a mixture of two isomeric compounds is obtained, althoughgenerally when using a substituted ortho-diphenylene compound the formation of the one or of the other of the two isomeric compounds preponderates according to the directing infiu- We claim: V

1. The process which comprises condensing a 1.4.5.8-naptha1enetetra-carboxylic acid with an ortho-diamine.

2. The process which comprises condensing a 1.4.5.8napthalenetetra-carboxylic acid with an ortho-diaminein presence of a dil- I uent.

,3. Process of preparing Vat dyestuffs, con sisting in condensing 1.4.5.8-naphthalenetetracarboxylic acid with a nitrated 1.2-diaminobenzene. V V

4. Process of preparing vat dyestuffs, consistlng 1n condensing a 1..5.8-napthalenetetracarboxylic 'acidwith an ortho-diamine V and halogenating the condensation product. ,5. The products which are obtainable by condensing a 1.45.8-napthalenetetra-carboxylic acid with an ortho-diamine the said products representmg a mixture of the two isomerlc dyestuffs of the following compositionsz -wherein X represents hydrogen or any substituent and R stands for hydrocarbon sub-' stituted or not.

6. The products which are obtainable by condensing a 1.4.5.8-napthalenetetracarboxylic acid with an ortho-diam'inojcompound of the benzene series the said products representing a mixture of the two isomeric dyestufis of the following formulae: 

